Moments Flashcards
What is the unit for mass
Kg
What is the unit for weights
Newtons N
What is a lever
A simple machine which uses a pivot
What is a moment
A moment is a turning effect of a force around a pivot
What is the equation for moments
Moments = Force x Perpendicular Distance
Unit of force
Newton
Unit of moment
Newton metre
Why does something topple
when weight acts outside the base of the object
When is the mechanical advantage for a lever
When only a small effort is needed to balance a large load
What is the principle of moments
For a balanced system(in equilibrium) the sum of all the clockwise moments equals the sum of all anti-clockwise moments
What is the centre of gravity
It is the point which the mass/weight appears to act from
It is the average position of mass
When is an object stable
When weight acts inside the base of an object
What are two things that make something stable
A low centre of gravity or a wide footprint
What are forces
A push or pull
What can they change
Shape speed or direction
What is hookes law
The force applied to an elastic material is directly proportional to its extension up to the elastic limit
What is the equation that links extension, force applied and spring constant
Force applied = spring constant x extension
What is elastic behaviour
When unloaded it returns to its original shape
What is plastic behaviour
When unloaded it shows perminent deformation and doesn’t return to its original shape
What is the point called where the object stops behaving elastically and starts behaving plastically
Elastic limit
Where is the elastic limit on the graph
When the line of best fit stops being straight
What does a stiff spring have
A large spring constant
What is gradient
Rise over run
What is spring constant measured in
Nm or Ncm
